1. Field of the Invention
The present invention relates to a method for producing ultra fine TiC-transition metal based complex powder, and more particularly, to a method for producing nano-sized TiC-transition metal based complex powder for use in a solid carbide cutting tool.
2. Background of the Related Art
TiC is known as a material added to WC—TiC—Co based solid carbide cutting tools to increase high temperature hardness and inhibit reaction with stainless steel to be cut. Also, it is used as a main ingredient of TiC based cermet tools. Recently, it has been found that when ultra fine powders of TiC based carbides are used in a tool, the tool has increased hardness, transverse-rupture strength and wear-resistance. Therefore, TiC based powder as fine as possible is used in production of tools or molds.
According to the conventional methods for producing TiC powder, a powder mixture of TiO2 and carbon or a powder mixture of titanium hydride (TiH2) and carbon is subjected to a thermal treatment at a high temperature of 1700° C. to 2000° C. in a non-oxidizing atmosphere, such as vacuum, inert atmosphere, hydrogen atmosphere, for reduction by carbon and carburization, to prepare TiC powder. However, such methods have disadvantages in that the invested cost of equipments is great and the power consumption is much, since reaction temperature is so high. Also, the produced TiC powder has a particle size of about 1 to 2 μm.
Meanwhile, the coarse TiC powder may be ball-milled to form ultra fine TiC powder. However, the TiC powder thus obtained has an average particle size 0.7 μm, and it is difficult to refine grains having such particle size. Also, during milling, impurities may be introduced to the powder.